Yarn feeders are accessory parts for weaving machines. They are normally not produced by the same manufacturers as the weaving machine. Said yarn feeders are universally usable for various types of weaving machines, and they are adapted to the respective weaving machine from case to case. Each yarn feeder is an independent unit having a separate drive means, a separate control of the drive means and separate monitoring and control elements. If several yarn feeders are associated with one weaving machine, they will be combined in a yarn feed system, which is installed separately from the weaving machine as a structural unit. The final consumer or rather the person making use of the weaving machine frequently buys the respective type of yarn feeder from the manufacturer of the yarn feeder, and he often asks the manufacturer to mount and to adjust the yarn feeder. Electronically controlled weft yarn feeders are equipped with an input and indicating section for functional parameters, such as the limit speed of the drive means, the weft yarn length, the sensitivity of the various sensors provided, the reference value of the weft yarn store size, the variation of the weft yarn store size, the weft yarn store offset and the like. These functional parameters are inputted by means of a keyboard and switches, and, if necessary, they are displayed by means of a display. In certain cases, a functional parameter is also changed while the machine is in operation. The display also serves to display mistakes or malfunctions in the case of operating trouble. The input and indicating section is provided on the housing of the weft yarn feeder at an easily accessible location. In a yarn feed system comprising several weft yarn feeders, a central control unit can be provided which has connected thereto all the weft yarn feeders. If the weft yarn feeders should then no longer have any separate input and indicating sections, the central control unit will be equipped in an appropriate manner. In practice, it becomes increasingly common to equip a weaving machine already at the manufacturer's firm with a weft yarn feed system, which is specially designed to meet the requirements of said weaving machine and which the manufacturer of the weaving machine offers and delivers as one unit together with the weaving machine. In spite of this fact, the independence of the weft yarn feed system has hitherto been maintained with regard to the adjustment of the functions in the weft yarn feed system presumably because the functional parameters of the yarn feeders are so different from the functional parameters of the weaving machine and because a direct connection between said functional parameters of the yarn feeders and the functions of the weaving machine does not necessarily exist, and because the yarn feed system is, in principle, structurally separated from the weaving machine in spite of the fact that it cooperates with said weaving machine when in operation. The independent adjustability of the yarn feeders in the weft yarn feed system by separate adjustment and indicating sections entails an inexpedient necessity of using additional devices. Moreover, the devices are difficult to operate, since the operating and control panel of the weaving machine is locally separated from the adjustment and indicating sections of the weft yarn feed system and has to be operated in a different manner in most cases. This may result in a loss of time and in misoperations on the part of the operators who have primarily been trained to operate the weaving machine.
Furthermore, it was suggested that a real-time data communication should be provided between the weft yarn feed system and the weaving machine so that, taking into account the complex sequences of functions and the high frequency of functions occurring in the operation of the weaving machine, there is communication between the weaving machine and the yarn feeder which facilitates the feed work of the yarn feeder and which increases the functional reliability of the whole system. The real-time data transmitted between the weaving machine and the yarn feeder in the case of such communication are significant trig-signals which occur in the program sequence of the weaving machine and which are processed directly in the program sequence of the yarn feeder. These real-time data do not have any influence on functional parameters for the yarn feeder. The functional parameters are set prior to putting the unit into operation.
The present invention is based on the task of simplifying the operability of an electronically controlled weft yarn processing unit, increasing the functional reliability of said unit and optimizing its range of use.